Leonids 2012: prediction of activity
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Fig. 1. Space-temporal projection of Leonids trails parts onto their minimal distance passages dirung the period (correspondence between colours of the particles and their ejection velocities can be seen here).
Fig. 2. Detailed space-temporal projection of Leonids trails parts onto their minimal distance passages in 2012 (correspondence between colours of the particles and their ejection velocities can be seen here).
Fig. 3. Assumed profile of overall Leonid activity (blue line) and its background component (red line).
Two Leonid peaks are expected during Leonids 2012 return - the background one and from 1400 trail. The first will be the background maximum, by IMO's data it occurs at solar longitude 235.27° (9:43 UT on 17 November). As in 2011, its intensity is expected to be quite low, around ZHR=10.
After the background maximum activity will begin to decrease and by 19:20 UT on 19 November ZHR should be only around 2. However, is shown on the Fig.2, some increasing fluctuations can occur and 1:26 UT on 19 November due to possible slight action of 1567 trail.
After that local minimun the second peak is expected, it is located in time quite far from background one, so its visual detection could be easier. 1400 trail particles should increase ZHR to 15 around 5:36 UT on 20 November. Meteor brightness is expected to lower a bit.
1. "Comet's dust 2.0" program by S. Shanov and S. Dubrovsky. [Used for orbital computations.]
2. Lyytinen E, van Flandern T. "Predicting the strength of Leonid outbursts", 2000, Icarus, P. 158-160.
3. Jenniskens P. Meteor showers and their parent comets, 2006, 780 p. 4. Kasuo Kinoshita, http://jcometobs.web.fc2.com/ [Orbital elements of the comet 55P Tempel-Tuttle]